Carotenoids, mainly derived from plant foods, have numerous essential roles in animals. For example, carotenoids are metabolic precursors of an essential component of vision, Vitamin A, and of other retinoid compounds involved in animal morphogenesis. Carotenoids also function as anticancer agents, as photoprotectors, as immunomodulating agents, and in enhancing cell communication. The prevalence of Vitamin A deficiency in developing nations due to inadequate carotenoid in the diet might be alleviated by engineering of appropriate genes into the major food staple in those countries, rice. Rice lacks carotenoids in the endosperm, the source of protein and starch. The focus of the research is the isolation and characterization of genes required for carotenoid biosynthesis in maize. Elucidation of regulatory mechanisms controlling this essential pathway will lead to strategies of engineering grains for improved carotenoid content. Maize is an excellent model system as its endosperm does make and store these essential pigments. Furthermore, the molecular studies are enhanced by the availability of many well characterized mutations blocking the pathway. Genes will be characterized with respect to physical maps, temporal and developmental expression profiles at RNA and protein levels, and effect of carotenoid mutations on expression. This research program is a concerted effort made by our MBRS undergraduates, predoctoral students, a postdoctoral fellow, and myself.